History

Older 386 and 486 PCs used RAM, at a single data transfer rate. This type of RAM was also known as DRAM. DRAM is common in older desktop computers.

Function

Today's faster CPUs all use some sort of SDRAM. SDRAM, or synchronous dynamic random access memory, is synchronized with the computer's internal clocking system. DDR memory uses a double pumping method of memory access and is faster than traditional RAM.

Types

DDR memory types are determined by the number of bytes per second that the data pumped through the RAM can handle. The bytes per second can be determined by multiplying the MHz by 8 bytes. DDR types are also identified by separate pins and guide notches for various types of computer systems. According to techterms.com, DDR2 is also available.

Benefits

DDR memory has a quicker transfer rate of information. This enables the computer system to function more quickly and spend less time processing information. DDR uses less power than RAM and is more efficient. It is therefore common in laptop PCs.

Considerations

DDR memory is volatile, meaning it only functions when the computer has power supplied to it. It is best to keep a backup of your work in the event that the power is interrupted. DDR memory is not permanent computer memory.

Source:

TechTerms.com